When horizontal subracks are configured in the electronic and communication equipment cabinet, horizontal subracks indifferent forms (for example, with a lengthwise air duct, or with a widthwise air duct) may exist in the same cabinet. FIG. 1 shows a horizontal subrack with a lengthwise air duct in the prior art. The horizontal subrack includes a board area 14. Boards are located in the board area 14, and a fan box 13 is located on the right side of the board area 14. The fan is installed in the fan box 13. A ventilation box is set on the right side of the fan box 13, and multiple air inlets 11 are set in the front of the ventilation box. An air deflector box 15 is located on the left side of the board area 14, and a first air outlet 12 is set at the rear of the air deflector box 15.
When the boards in the board area 14 need to dissipate heat, the external airflow enters through the air inlet 11. Under the effect of the axial flow fan, the airflow enters the board area 14 to dissipate heat for the boards in the board area 14, and then flows out of the first air outlet 12 of the air deflector box on the left side of the board area.
In the process of developing the present invention, the inventor finds at least the following defects in the prior art:
The horizontal subrack uses an axial flow fan to dissipate heat. Because the widthwise dimension of the horizontal subrack is limited, the axial flow fan blows the cool air onto the board directly. As affected by the fan hub, the cool air from the fan is not mixed sufficiently before arriving at the board area. Consequently, the air volume is not even for the board slots in the board area of the horizontal subrack, which is a bottleneck of enhancing the heat dissipation capability of the horizontal subrack.